Williams system 6 repair help

[ronnie63]

I'm currently trying to get a sys6 TW working, it had leaking batteries! but no damage whatsoever on the cpu, the driver board below had some white residue on the legs of the pia and a few smaller chips close by, again non corroded areas of the board and the 40 pin interlink is also clean and looks good. I either get 2 solis red led's (mostly) or they don't come on at all, no displays and only GI's lit.

Things I have done so far, re capped the power board, replaced all the cpu sockets, checked for good 5v and 10v unregulated, checked for burnt connectors.

One thing that stuck out was the 5101 static ram but this is hard soldered to the board! I do not want to remove it unless I can prove it's faulty!

I have looked at the repair wiki which is great and goes into great detail, but I find it confuses me switching from sys6 to sys 7 I get lost!

I was looking at a bit last night which explains using a 6802 instead of a 6808 but can't find it lol! I have some new 6802's to maybe rule out cpu failure?

Also a bit on using a single rom to replace the 5 masked one's, I do have a wilem programmer but not sure if I have any 2716 or 2732 roms

I do have a logic probe decent fluke DMM and a scope, any pointers to talk me through checking for instance the 5101 or any other help would be apreciated.

Thanks Ronnie

P.S I have cleaned the driver board up after this picture!

 

[Jay Walker]

As far as the choice of cpu chip, a 6802 can be used instead of a 6808. The '02 has its own internal Ram, so a jumper change* to enable this allows one of the 6810 Nmos Ram's to be removed (the one in a socket).

* R4 (4.7 K Ohm) to 5v, rather than J1 to ground enables the chips' internal Ram

 

[ronnie63]

As far as the choice of cpu chip, a 6802 can be used instead of a 6808. The '02 has its own internal Ram, so a jumper change* to enable this allows one of the 6810 Nmos Ram's to be removed (the one in a socket).

* R4 (4.7 K Ohm) to 5v, rather than J1 to ground enables the chips' internal Ram

Thanks Jay, I went ahead and tried the 6802 removed J4 and fitted the 4.7 k resistor at R4 but the results were the same! I'm about to remove the driver board to see if it's hanging the cpu

Thanks Ronnie

 

[ronnie63]

There is no change with the driver board removed, still 2 solid led's. I'm thinking at this point I could power the mpu on the bench for easier probing once I know what to probe lol

 

[Moonraker]

5101 RAMs are incredibly flakey and well known for going wrong, so I'd look at that first over 6808 or 6802 which are normally far more robust. You can carefully remove the 5101 then socket it. You can swap it with another to see if it's working or not. There is a test rig that you can buy for 5101s.

 

[Moonraker]

Scroll down to find inquisitor IC testing

http://lockwhenlit.com/products.htm

 

[ronnie63]

5101 RAMs are incredibly flakey and well known for going wrong, so I'd look at that first over 6808 or 6802 which are normally far more robust. You can carefully remove the 5101 then socket it. You can swap it with another to see if it's working or not. There is a test rig that you can buy for 5101s.

Thanks, yes I was thinking that as remember them from the Bally boards! I do have some new one's so that could be an option. The thinking on the 6802 was it would prove the cpu and that other ram chip at IC13?

Thanks Ronnie

 

[ronnie63]

Scroll down to find inquisitor IC testing

http://lockwhenlit.com/products.htm

looks cool, would you need to buy all the blades to go with it?

 

[Moonraker]

looks cool, would you need to buy all the blades to go with it?

Only the ones you need or might need - eg you need SRAM to test 5101, but you ought to get PAI/RIOT blade as 6821 can be a real pain to figure out if they go wrong. I'd buy the assembled version, costs a little extra but the time saving is enormous!

 

[ronnie63]

No way I'm getting that 5101 out in 1 piece! Tried sucker, debraid and flux! It's one of those old style ceramic flat chips with brass legs! I dare not use the rework gun on the pcb!

 

[ronnie63]

Like this!

 

[ronnie63]

I managed to get it out! Used turned pinstrip, tried 3 types of 5101, still the same!

 

[stevebm1]

have you tried using leons test rom in the board?,it also worth replacing the 40 pin interconnect on the driver board if it looks a bit flakey with age as sometimes they loose tension on the pins

 

[ronnie63]

have you tried using leons test rom in the board?,it also worth replacing the 40 pin interconnect on the driver board if it looks a bit flakey with age as sometimes they loose tension on the pins

I will probably need to, not got a 2716 to hand, that interconnect molex looks good clean and tight

Cheers Ronnie

 

[ronnie63]

Found a load of 2716's luckily, hoping my Wellon vp-280 does these, at leat it's coming up with M2716A in the device list?

Maybe I could also verify the roms are good if it will read those lasked roms?

Thanks Ronnie

 

[ChrisFormela]

First of all, start with new single ROM. Your willem won't program it (21V required) but there is a guy on ebay who sells ROMs with programming for around £10. This will solve 2 potential problems (sockets and ROM) I recently had similar problem with my Flash

 

[ronnie63]

First of all, start with new single ROM. Your willem won't program it (21V required) but there is a guy on ebay who sells ROMs with programming for around £10. This will solve 2 potential problems (sockets and ROM) I recently had similar problem with my Flash

Ah that's a bummer! it has a psu but not 21v! I guess same for test rom? I have already replaced the sockets but a bad rom could be the culprit

Cheers Ronnie

 

[stevebm1]

I burned the test rom on a gq-4x a few years back without 21v ,sadly no longer have it though,as I lent it to someone and they lost it,they did reinburse me though,but I bought a mini-pro instead

 

[ronnie63]

I burned the test rom on a gq-4x a few years back without 21v ,sadly no longer have it though,as I lent it to someone and they lost it,they did reinburse me though,but I bought a mini-pro instead

Was that on a 2716 Steve?

 

[stevebm1]

yes it was

 

[ronnie63]

Reading the guide the flipper roms should be in location ic20 and ic 17, in mine they are in 20 and 14, 17 is empty, would this matter? I'm thinking it was working like this at one time.

Thanks Ronnie

 

[ChrisFormela]

I burned the test rom on a gq-4x a few years back without 21v ,sadly no longer have it though,as I lent it to someone and they lost it,they did reinburse me though,but I bought a mini-pro instead

There are AMD versions of that chip that require only 12V but are quite rare. I've tried to use my Willem to flash it so Im 100% sure that 21V is required. You can use ch431 amd inject 21V from the lab PSU.

 

[ronnie63]

There are AMD versions of that chip that require only 12V but are quite rare. I've tried to use my Willem to flash it so Im 100% sure that 21V is required. You can use ch431 amd inject 21V from the lab PSU.

Mine are Mostek, comes up fail when writing but verifies as ok, away to try it on the mpu

 

[ronnie63]

It seems to have worked! I'm mostly getting 4 flashes on both leds before they stay lit? But odd times 1 flash? Not even sure what I should learn from these flashes?

Thanks Ronnie

 

[Jay Walker]

As I recall, 'Flipper Rom 1 (and 2)' should be in the bottom row, left and centre respectively, with either a specific Game Rom at the right hand end, or with three proms in the upper row, as I see in the cpu picture above. I'd think it would matter, as the sockets are addressed individually. I think that the fitment of J3 or 4 depends which set-up is used.

The two l.e.d.'s don't actually seem all that useful. My recollection is that they blink twice for a successful boot sequence, or maybe when the on-board test button's pressed*. Other combinations supposedly indicate memory device problems, I think the possibilities are shown in the Williams 'Solid State Flipper Repair' general-purpose manual.

* and provided the door's open

 

[ronnie63]

As I recall, 'Flipper Rom 1 (and 2)' should be in the bottom row, left and centre respectively, with either a specific Game Rom at the right hand end, or with three proms in the upper row, as I see in the cpu picture above. I'd think it would matter, as the sockets are addressed individually. I think that the fitment of J3 or 4 depends which set-up is used.

The two l.e.d.'s don't actually seem all that useful. My recollection is that they blink twice for a successful boot sequence, or maybe when the on-board test button's pressed*. Other combinations supposedly indicate memory device problems, I think the possibilities are shown in the Williams 'Solid State Flipper Repair' general-purpose manual.

* and provided the door's open

Thanks Jay, it would seem the right flipper rom is fitted wrong. As far as I know it did work like this.

I tried to find a guide to expected led flashes but found nothing, it explains the test rom on the repair guide but for me it seems to go on and on and no bullet points on expected behaviour. Also I have the board on the bench with everything removed roms ram etc

Thanks Ronnie

 

[ronnie63]

So I have put back the 6808 cpu and altered the jumper removed the resistor to suit. I had the test rom at IC14 and have now switched it to IC 17, now things are more stable as in both leds flash together consistantly. Is it now waiting on the driver board to go further?

Thanks Ronnie

 

[Jay Walker]

You're making progress, then.

Rather than pop home to dig up the paper copy, I've poked around on ipdb. The material for Flash, while it's Level 4, has the led combinations, and mentions powering the Cpu board on its own. Then, they should flash twice and go out.

The upper l.e.d. off and lower one on is (it says) Rom/Prom failure, (17,20,21,22,26). The upper one lit and lower one off is Ram's, 13 & 16, while both lit is Cmos Ram or PIA 1.

That applies to ordinary software rather than any subsequent test devices, obviously.

 

[ronnie63]

You're making progress, then.

Rather than pop home to dig up the paper copy, I've poked around on ipdb. The material for Flash, while it's Level 4, has the led combinations, and mentions powering the Cpu board on its own. Then, they should flash twice and go out.

The upper l.e.d. off and lower one on is (it says) Rom/Prom failure, (17,20,21,22,26). The upper one lit and lower one off is Ram's, 13 & 16, while both lit is Cmos Ram or PIA 1.

That applies to ordinary software rather than any subsequent test devices, obviously.

Thanks Jay, at the moment I have the 5101 and ram at IC 13 removed the other ram is soldered, I will try adding these back and see what happens, From what I read I need to check the outputs of the pia whilst test rom is running, and if all good maybe attach the driver board to see if it still runs or hangs!

Thanks Ronnie

 

[ronnie63]

Ok rams put back still flashing and cpu pia is toggling all the outputs so that looks good, Have attached the driver board and checked the 3 pia's, the one that sits vertical below the batteries and had some damage to the legs is dead! The other 2 below the 40 pin connector both test good. Not sure what to check next, away to read up some more

Ronnie