Wednesday, 29 February 2012

Well, that explains things...

So, it turns out that the warped image that my universal chassis was showing is due to an incompatibility between the Sharp Image chassis and the Phillips tube that I paired it with. Boo hoo! That means that comparing the Blaupunkt and Sharp Image isn't really a fair contest since the Sharp Image is working with a monitor it doesn't like. Here's what Joey from Jomac had to say:

"Mate honestly that picture looks awful , I know exactly what's causing it but it's not something I can do remotely or without the same tube here , I wouldn't be happy with that either the way it is. , fortunately it's not a issue with most tubes , for some reason it only appears on some of the Euro types with moulded yokes but still not all , I think you would have heard by now if this was a general issue."

I guess that means that the images I posted aren't really indicative of how these chassis usually operate. It also means that I'm out of luck in when it comes to a universal chassis.

Tuesday, 28 February 2012

Blaupunkt vs Sharp Image

Which would you choose? The winner is clear to me... Remember, we're comparing a $30 SCART television with a $240 arcade chassis...

Sharp Image universal chassis
Blaupunkt (left) versus Sharp Image (right)

Sunday, 26 February 2012

Pots progress

I received a few packages last week: 1 from Digikey, 1 from Jomac and 1 from Ozstick. After getting straight into the latter two (and subsequently feeling pretty disappointed with the combined result), I spent today working with the 6 Vishay potentiometers I bought from Digikey for my Blaupunkt IS70-33 VTN television.

It was a pretty fiddly operation and soldering was sweaty work on a 34 degree Celsius day. However, it was a complete success! I now have external analogue controls for V-size, V-position, H-size and H-position (pincushion and trapezium are still to come). I even wired things so that the direction of the pots is intuitive (e.g. clockwise expands the height, anticlockwise moves the image left). With these controls outside the TV case and at the front of the screen, I can now quickly perfect the borders for every game I load up in GroovyMAME!

The cool thing with this setup is that you don't have to compromise. GroovyMAME does a great job of centring the image for each modeline and gets pretty damn close in most cases. With these extra knobs for size and position controls I can quickly account for the last few millimetres and get things PERFECT. The other cool thing is that you can adjust for games like Metal Slug that normally has a built in border. Once the pots are mounted in the TV casing (meaning I don't have to pick each one up to adjust), the whole process will be under 10 seconds for each game.

Now I just need to drill some holes! I practised today on a spare Loewe input plate that I have. However, the plastic started to tear and rip once the drill bit got halfway. Probably gonna need a better drill than the crappy Ozito I borrowed from work. Can't wait to finish this little project!

External controls held in place by a Siemens RC
Metal Slug minus the borders
Bubble Bobble spot on!

Saturday, 25 February 2012

My second ever Siemens

Siemens TVs are pretty rare in Australia. I've only seen four in my time: 1 under a ton of hard rubbish, 1 on eBay (which is now in my lounge room), 1 in an alley way (with spray paint over the screen) and another recently advertised on eBay (keeping my other Siemens company in the lounge, as of today).

Siemens televisions house chassis made by Grundig. The first Siemens I bought was a digital chassis whereas the one I picked up today has a stack of lovely analog trimpots (Siemens chassis CS 9106 = Grundig chassis CUC 5630).

Having spent some time today messing with my new Sharp Image universal chassis and, frankly, feeling pretty disappointed by the geometry, I fired up the new Siemens to see how it compared. As I suspected it would, it kicks ass! Using the trimpots at the back you can get the borders nicely in MAME before starting a game. With the universal chassis it's much more of a compromise whereas the CUC 5630 let's you get very close to perfect geometry. Pretty crazy considering the Siemens cost me AUD $10 and the Sharp Image was AUD $240!

Hopefully I'll have a detailed comparison written up soon...

Siemens FS 237 M6 (chassis type CS 9106)
Say your prayers dust, tomorrow you meet my air compressor!

Friday, 24 February 2012

Universal chassis arrives!

My universal chassis from Jomac arrived yesterday! I feverishly hooked it all up last night. As a start, you can read a little about my experience here. I'll have a full report posted sometime on the weekend. Gonna be fun putting this thing through its paces!

Sunday, 19 February 2012

Game Over

Something bad and sad happened today. After a flurry of tube swapping, my antique Grundig CUC 4635 chassis went up in smoke. I left one of the connectors off (not the HV anode though!) after swapping the chassis back from testing a different tube. When I powered on there was a hiss, some smoke and then a sinking feeling in my stomach. I found the burnt resistor and replaced it but it was no use. There must have been some further damage down the line. Since I don't have the skills needed to repair something so complicated I took a deep breath and started tearing it down. I put all the circuit boards in a cardboard box and off it went to the tip with a pile of my other junk. Pretty sad. This was the best chassis I've tried so far and I reckon the chances of another one coming along in this day and age are pretty slim. Luckily, I had just ordered a universal chassis from Jomac so I didn't cry. I guess it was good to get my experimenting out of the way using a chassis I paid $0 for. I still kicked myself though! Oh well. Live and (hopefully) learn.

RIP Grundig


Did a bit of monitor rewiring last night and made this humorous mistake! I guess the ordering of the inputs is important after all...
Upside down, upside down.

Saturday, 18 February 2012

Finally, a Loewe that will play R-Type!

Just picked up a Loewe Profil Plus 3472 that was offered as a freebie on Gumtree.

This TV seems to be something of a transition model for Loewe as it's not a 100 Hz chassis but it runs the same Super Flatline tube used in the later models. Also, the internals are very much like an E3000 but the menu system is closer to that of the later Q2500 and such.

Anyway, I was curious to see if this unit had the same issues as the E3000 when it comes to showing games with 256 lines. It was a nice surprise to see that it will display the full image for R-Type and, as a bonus, doesn't have the trapezium distortion issue of the E3000 when displaying refresh rates that aren't strictly PAL or NTSC. Very cool!

I suspect this chassis still has a few quirks that make it less than ideal (in terms of fast modeline switching) but the picture quality is great (vivid, focussed, stable, etc.) and it's nice to finally see R-Type on a Loewe after all my previous failed attempts.

All four borders visible? Check!
In game
Profil Plus 3472

Wednesday, 15 February 2012

An artist's impression

My girlfriend has her own blog called 100 days of drawing. She's always looking for something to capture with her pencil and she recently drew one of my TVs with the guts hanging out the back... nice!

Sunday, 12 February 2012

Grundig in Blaupunkt

Today I cleaned up the mess I made on Saturday and then did some more tinkering. After my experiment yesterday with tube swapping, I couldn't get over how good my ancient analog Grundig looked with the Loewe CT1170 Phillips tube attached. So, I got to work and mounted the Loewe tube in a cool looking black case from a digital chassis Blaupunkt that had stopped working. That's parts from 3 seperate TVs in total! Not sure if the Grundig chassis will properly fit inside the Blaupunkt case yet... gonna require some careful thinking and reworking of external controls. I had to use the Blaupunkt case rather than the Loewe CT1170 as the audio amp in the Grundig is 4 ohms. The speakers in the Loewe are 8 ohms so they wouldn't match up. Either way, it was a fun adventure and the image looks AMAZING running GroovyMAME. Probably the best I've seen so far!

Unfortunately, I'm not sure if the Grundig chassis will last the distance as the flyback and other transformer look really tired. It'll be fun in the meantime though!

Loewe screen + Blaupunkt case + Grundig chassis = big mess!
Produces a sharp, vivid image...
... that is solid and very well focused.

Saturday, 11 February 2012

Patching geometry controls (and tube swapping!)

After messing around with my analogue chassis Blaupunkt IS 70-33 VTN last week, I started to realise how fast and easy it is to adjust the sizing and geometry of these TVs compared with their digital counterparts. With digital, you have to enter the service menu, navigate to the required section or menu, select the value you want to edit, save the value, exit the service menu, reset, etc. Of course, every brand is different but, basically, these types of TVs give you great options for setting up a perfect picture for a single resolution. However, when using MAME, we want to change the resolution quite often (unless you only every play the same game, of course!) That means frequent trips to the service menu which gets very time consuming.

With analogue TVs (the ones I've tried at least) there are a series of trim pots that adjust the picture size and shape. On my Blaupunkt you have to take the plastic casing off to access them. They're also on the mainboard at the very rear. To adjust them, watch the picture and also avoid getting electrocuted is pretty hard to do! So, I got thinking: "what if I ran a patch cable from the mainboard to the front of the TV so that I could adjust the picture and see the resultant changes?" Well, today I did just that! Instead of attacking the Blaupunkt straight away, I decided to mess with my analogue Grundig first. Since GroovyMAME can be setup to provide near perfect resolutions for each game with only height adjustments needed on the monitor, I decided to start with this control.

The great thing about this Grundig is that there are a series of daughter boards that can easily be removed for servicing. All the controls for size and geometry are on the one card.

First, I desoldered the vertical size trimpot using some solder braid:

Nice clean holes
Here's the potentiometer in question:

100 ohm variable resistor
Then, I soldered the 100cm patch leads to the legs of the pot:

Nothing beats colour coded heatshrink!
After that, I soldered the other ends to the daughter board:

Where's my V-size pot gone?!
Stuck the board back in the TV alongside the others:

Various daughter boards including RGB, audio, tuner, etc.
Moment of truth time... I turned on the TV and hoped for the best. Initially, the picture was all messed up because the other pots had moved position when I cleaned the daughter board. However, the externalised vertical size pot worked just fine! And, it was such a joy to be around the front of the screen while adjusting the height!
The vertical amplitude pot is on the floor in front of the screen
After that success, I made patch cables for the other 5 controls (vertical linearity, vertical position, horizontal size, pincushion and trapezium). I made this shorter (250 mm) to avoid a big tangle. I just wanted to get them out of the electrocution zone since they were really tricky to get at while the TV was running.

The other trim pots removed
Leads attached
After patching the leads, I was able to work out exaclty what each control did (the list I gave before was unconfirmed before this process). Unfortunately the vertical position pot was extremely brittle and the turning part literally crumbled after a few turns. Oh well. Gonna need a new one. I guess that's what 20 years of cooking inside a TV does to you. Also, I couldn't find a horizontal position pot. Not sure if this will be a problem or not...

The long term plan is to get hold of some proper panel mounted pots and drill holes into the front panel of the TV, underneath the front of the screen. That way once GroovyMAME has done it's best to get everything sized and centred I can do the last few tweaks with hardware. I reckon it's going to be a killer system!

Now... this is where the day got wacky. After the success of my trim pot experiment I couldn't help fiddling with some other stuff. Long story short, I ended up performing a full tube swap! I took the awesome Phillips tube out of a faulty Loewe CT1170 and attached it to this Grundig chassis. Amazingly, it worked first try! Considering that I'd never even discharged a monitor before today I was pretty pleased with myself. The best part is that this old school Grundig chassis hooked up to the high-end Loewe tube looks AWESOME.

This whole process is worthy of a blog entry in itself but time is getting away from me... crazy day of television hacking. Gotta get some sleep then clean up the huge mess I made in the morning.

Grundig analogue chassis with the tube from a Loewe digital! Oh yeah!
Minecraft at 240p anyone?
Home made discharge tool
Super vivid R-Type Leo
Wow, what an adventure. I can sense a new obsession coming on... tube swapping! Enough already!

Saturday, 4 February 2012

Free Grundig and bag of nectarines!

Seeing as I'm on a mission to slim down my SCART TV collection I deleted all my saved eBay searches and told myself I'd have a 1 month moratorium on the acquisition of new TVs. Problem was that when I went to the Gumtree website to see if I could advertise some of my units there, I discovered someone giving away a vintage Grundig! I couldn't resist!

So, last night after work I went for a half hour drive down the coast and headed up into the hills. The countryside was really pretty and the weather was fantastic which made for a very enjoyable trip. When I arrived, I couldn't believe how scenic the place was:

Admiring the scenery
The folks giving away the TV where really sweet and insisted I take a few other things (keyboard, DVI cable, some brand new VHS tapes) and also a bag of home-grown, organic nectarines! Yum!

Fuel for alert gaming
Now, for the main attraction! The TV itself is a Grundig ST 70-460 S/text with a CUC 4635 chassis.

The small print
"I am Grundig."
The extremely dusty chassis
Street Fighter II up and running
The owner said that one of the speakers didn't work. When I pulled the back case off I found that the non-working speaker simply had a loose plug. Unfortunately, the so-called "working" speaker had a rubber surround that had completely perished. However, the speaker system is a 2-way (unusual) and there is also 4-ohm output for external speakers!

One minus is that the remote refuses to talk. Gonna have to see if my Logitech universal remote will drive this telly.

Most importantly, the image looks awesome! Great geometry, focus and color. The picture is really solid (no jitter or waviness) and the older Phillips screen has a lovely soft look that is probably more arcade authentic than the later model Phillips I'm used to.

Keen to clean this baby up and put it through its paces!