Drive talkin'....

[Etienne MacGyver]

Sure, i will come over to help and bring the desolder station.

But maybe bart want to do this himself, i thought he had a desolder station also ?
its not that i dont want to help, but i dont want to spoil it because you wanted to do it yourself.

Let me know, and i'll act to it 

[level42]

Ah yeah I think you're right !

[level42]

OK for what it's worth here is the list as I found the caps on two Hard Drivin' 25K5515 chassis:

The deviations from the K4900 list I found are confirmed on BOTH chassis and are original caps (all caps are Elna's on both chassis)


C201 1000u 16V (not 100uF as often mentioned !)
C205 470u 16V
C301 330u 50V (not 25V !)
C303 2.2u 50V
C308 2.2u 50V
C310 10u 160V
C311 10u 160V
C313 100u 160V
C315 1u 50V
C351 1u 50V
C352 47u 25V
C354 47u 25V
C506 22u 160V
C507 47u 160V (not 200V but OK...)
C701 1000u 25V
C702 10u 100V (Not 160V or 200V but OK)

C505 560u 200V (that one is probably also on the K4900 but it's never listed because it's big (the filter cap))


So far not too shocking. Now the only extra's I found:

C100 47u 25V (this is on the elevated small pcb on the left of the chassis)
Also there is a cap piggy-backed over D306 @ 1uF 50V

I'll post an updated cap-map tomorrow.


For the record, these are the one's I found to be bad:

Chassis with burned out HVT:
C201,C310, C701, C702

Chassis with OK HVT:
C201,C205,C701

What I found a bit amazing was that most showed a (much) lower capacity and not a bad ESR. Some 1000uF one's were less than 500 uF now.
I think only 2 or 3 had a bad ESR. All in all not too many bad caps and the tester already proved it's use

[level42]

Well today I had to work in 020 again and so I agreed with Polder to drive to him from work as he lives pretty close to 020.

I had brought both HD PCB sets, the working one to test, the other one so Polder can have a go on it with his desoldering station and replace even more RAMs....

Also brought the two fixed monitor chassis.

First put back one chassis and hooked it up completely to the tube and the power. We didn't  connect it to the board, let's first see if it powers up OK.

Well, power on and a small flash white flash near where the fuse is. No power up sound, nothing. So.....we're not there yet.
For the other chassis the HVY hadn't arrived yet so we couldn't try that one.

So it was back to the VGA converter and LCD screen for testing the game PCB set.

Installed it in the "most beautiful" of the two cabs and to my excitement it passed ALL tests.
Even the sound board was checked OK. It does give a ROM check error on the sound board, but I read on Jed Margolin's site that this is normal behavior. And indeed it worked pretty well !
However, the steering pot meter must be completely gone on this cab. It's (apparently) producing all kind of weird values because I was steering straight but the car went in all kind of directions. We tried to read in the pot meter values again (calibrate) and it indicates that the "high" value is too high so there has to be something wrong. Because of the weird pot values, the motor steers the wheel like nuts in all kinds of direction, pretty forcefully !

Anyway, it was impossible to even try a bit of a game on this cab.

SO we moved to the second cab. This one doesn't have the looks, but seems to have more parts working....
Anyway, it passed all tests again and we tried another game:

http://youtu.be/WDxXodYsIww  (sorry, crappy phone cam shots, was all I had with me...but you get the idea

Works pretty well !! If we'd have a proper syncing on the VGA card we would have actually been able to try a decent game.

However, both cabs seem not to go in automatic shifting for some strange reason, and the shifters on both have some troubles.

Anyway, we are one big step further. Going to have to check the monitor chassis next why the fuse blew....

[Etienne MacGyver]

COOL !

[gyruss]

020, 020? What does that mean, please explain! 

[level42]

020, 020? What does that mean, please explain!  

LOL !

I think I already figured out why the fuse blew on the monitor chassis and the reason is freaking embarrassing.

I had previously removed the HOTs (Horizontal Output Transistor) on both chassis to measure them for any shorts and examine the condition of the thermal grease (paste). After 30 years it usually dries out completely and even seems to "disappear".
Probably, when I did this I decided to throw away the mica insulators and cleared the area with some alcohol because the grease is messy and also poisonous. Since there was some time between "sessions" I apparently had forgotten that this HOT needed the insulator and so I mounted it directly to the chassis.....brilliant !

O well, at least I have plenty of mica insulators now, so this is a very easy fix ! Now all I need is a pig-tail fuse but since I hate these things I probably will put in some decent fuse holders and a regular fuse....

[Etienne MacGyver]

That is a logical explanation 

[level42]

I probably will put in a Euro sized fuse holder so I can use normal sized fuses instead of US sized. These fuses are easier to get here and thus probably cheaper. Luckely one of the tracks runs for a great part under the current fuse so it is possible to drill an extra hole for that.

The guy who invented pig-tail fuses should be sentenced to ten years !!!! What a stupid way to save a couple of cents during production....before I started this hobby I never even knew they existed !!

[level42]

Done !

This is what the pig-tail fuse looks like...this one has a cover. It's a normal fuse with two little wires connected to them. They are directly soldered to the PCB....sigh.


So I desoldered them from both chassis, got out the Dremel (fake one) and drilled an extra hole in the track running to one of the fuses ends. Luckely WG decided to make the track run straight under the fuse so this made it easy !
I also had to drill out the other (original) hole a bit because else the new fuse holder didn't fit.

Had to scrap off the protective layer so there would be a new "copper" soldering island:



And this is how it looks now, and how it should have been in the first place....



Look at that TIGHT looking transparent fuse cap HAH !

Both chassis ready for testing now (that is, one still needs a small part called the fly-back, but it has arrived at Polder's place !).

I hear polder still has trouble with RAMs being (going) bad.....man that sucks !!

[level42]

Tomorrow night will be the second try to get the monitors running again at Polder's place.

We'll need to install a fly-back in one of the chassis and then it's testing time again....really hope the few caps I replaced will do the trick :S

If all goes well one of the HD's will be transported to my game room next saturday.

[Superully]

i'm always somewhat afraid when putting in a chassis after having worked on it - you never know what to expect: fireworks or fire up!

[baritonomarchetto]

[...] you never know what to expect: fireworks or fire up!

... or the same behaviour it has before the repair   

[level42]

i'm always somewhat afraid when putting in a chassis after having worked on it - you never know what to expect: fireworks or fire up!

Yeah, isnt this hobby exciting ! 

Well we already had plenty of fireworks on one Flyback, Im pretty sure the new one wont give a show like that (at least for some time )

[Belike]

There are some parts for sale for this cab on jamma+:
"Hi,
I have a Driver Sound and an ADSP II board from compact hard drivin'.
Totally untested, I got these in a job lot and don't have a Hard Drivin' cabinet.
I'm asking $20 per board on VAPS so I'll ask the same here.
I also have the 8 original ROMs (verified) + 136068-1168 chip (untested) for $30.
IBAN+BIC transfer accepted, PayPal also (grudgingly :-) accepted.
If you want to do a trade, I'm looking for any Marble Madness parts or a whole kit (I'll naturally pay the difference if we come to an agreement)."