SpeedyTT, black screen of death !!!! HELP

[zfrenchy]

here is the results of my testing, the red X are the continuity fail (red number are the test #, not the pin #)

Screen Shot 01-07-26 at 06.54 PM 001.PNG (2.4 MiB) Viewed 171 times

Anyone know where is R950 is on the board ? I cannot find it.

Screen Shot 01-07-26 at 06.54 PM.PNG (825.05 KiB) Viewed 171 times

[HigashiJun]

Ouch, that's pretty bad...



Now you have to bodge wire all the missing connections.

[frank.lukas]

You need a professional electric vacuum desoldering pump and experience for this kind of work. It's a multilayer circuit board and therefore quite delicate. If in doubt, clip off the IC pins and desolder them individually using tweezers.

A manual desoldering pump is completely unsuitable.

[Atarian Computing]

Anyone know where is R950 is on the board ? I cannot find it.

You have a later revision TT that never had the schematics published by Atari. The only schematics available are for the PGA revision so there is bound to be minor differences.

[zfrenchy]

You need a professional electric vacuum desoldering pump and experience for this kind of work. It's a multilayer circuit board and therefore quite delicate. If in doubt, clip off the IC pins and desolder them individually using tweezers.

A manual desoldering pump is completely unsuitable.

I have a Hakko 470

[zfrenchy]

Anyone know where is R950 is on the board ? I cannot find it.

You have a later revision TT that never had the schematics published by Atari. The only schematics available are for the PGA revision so there is bound to be minor differences.

Ok. Thx

[12-MHz]

here is the results of my testing, the red X are the continuity fail (red number are the test #, not the pin #)

Hi zfrenchy,
it is best to re-solder all pins of the GALs and the 74LS74.

Anyone know where is R950 is on the board ? I cannot find it.

Yes, indeed. Look at the attached picture.
In some boards, R950 has a value of 33 ohms.

Best regards
Robert

IMG_6097.JPG (815.63 KiB) Viewed 108 times

[zfrenchy]

here is the results of my testing, the red X are the continuity fail (red number are the test #, not the pin #)

Hi zfrenchy,
it is best to re-solder all pins of the GALs and the 74LS74.

Anyone know where is R950 is on the board ? I cannot find it.

Yes, indeed. Look at the attached picture.
In some boards, R950 has a value of 33 ohms.

Best regards
Robert


IMG_6097.JPG

Can you shot to me another photo of you board top silkscreen including the region of the CPU ?
It will be handy to see the traces whitout the component.

[zfrenchy]

ALL FIXED, hoping not coming back here when I will install the SpeedyTT, Storm and LighningVME.

At the end, it was only some point to resolder, and a new budge wire between U11 pin 17 and U112 pin 2, no component damaged so far, will see after a while.

20260110_112737.jpg (264.3 KiB) Viewed 55 times

[Icky]

Glad you got it working again. Always a nervous time when we do work on these old systems and they stop working.

Let us know how you get on with the SpeedyTT, Storm and LightningVME.