TT030 C302406-001 REV H

TT motherboards.
Steve
Posts: 2658
Joined: Fri Sep 15, 2017 11:49 am

TT030 C302406-001 REV H

Post by Steve »

It has a very strange multi-layered modification on the sound chip people haven't seen before. Does anyone know what that was for? Thx.

edit: updated the title to rev H as suggested by Atarian Computing.
20170304_112017.jpg
20170304_112017.jpg (6.08 MiB) Viewed 8130 times
20170304_112025.jpg
20170304_112025.jpg (6.04 MiB) Viewed 8130 times
20170304_112030.jpg
20170304_112030.jpg (5.83 MiB) Viewed 8130 times
20170304_112044.jpg
20170304_112044.jpg (4.48 MiB) Viewed 8130 times
20170304_112053.jpg
20170304_112053.jpg (5.63 MiB) Viewed 8130 times
20170304_112904.jpg
20170304_112904.jpg (4.78 MiB) Viewed 8130 times
IMG_20180718_212130.jpg
IMG_20180718_212130.jpg (1.39 MiB) Viewed 8130 times
^ Oddly on the top of the motherboard in the bottom right hand corner where it says REV_____ it has a very faint hand stamped 'B'. I don't know why that doesn't correspond with the PCB revision on the underside pictured above.
Atarian Computing
Posts: 445
Joined: Tue Aug 22, 2017 4:27 am

Re: TT030 C302406-001 REV A

Post by Atarian Computing »

Nice pictures! TT revisions are a mess. Your's probably is a REV.H. I've seen many C302406-001 REV A boards with REV.H topside.
User avatar
exxos
Site Admin
Site Admin
Posts: 24066
Joined: Wed Aug 16, 2017 11:19 pm
Location: UK
Contact:

Re: TT030 C302406-001 REV H

Post by exxos »

Interesting.. Pins all bent on the IO ports on the YM chip.. Wire goes to "DD enable" to the 1772 by the looks of it. I will take a guess its a factory fix ? Maybe you could take out the YM chip and see if there is any tracks visible ?
https://www.exxosforum.co.uk/atari/ All my hardware guides - mods - games - STOS
https://www.exxosforum.co.uk/atari/store2/ - All my hardware mods for sale - Please help support by making a purchase.
viewtopic.php?f=17&t=1585 Have you done the Mandatory Fixes ?
Just because a lot of people agree on something, doesn't make it a fact. ~exxos ~
People should find solutions to problems, not find problems with solutions.
Atarian Computing
Posts: 445
Joined: Tue Aug 22, 2017 4:27 am

Re: TT030 C302406-001 REV H

Post by Atarian Computing »

I'm certain that there are two revisions of REV.H. Let me show ya:

Here is the earlier revision from this forum:
20180121_104548.jpg
20180121_104548.jpg (3.24 MiB) Viewed 8101 times
InkedTTha_LI.jpg
InkedTTha_LI.jpg (726.05 KiB) Viewed 8101 times
InkedTThb_LI.jpg
InkedTThb_LI.jpg (860.32 KiB) Viewed 8101 times
InkedTThc_LI.jpg
InkedTThc_LI.jpg (1 MiB) Viewed 8101 times

And another early H.
IMG_0030.JPG
IMG_0030.JPG (231.8 KiB) Viewed 8101 times

Here is proof that C302406-001 REV A boards can be REV.H
Atari_TT_Rev____unten_rechts.jpg
Atari_TT_Rev____unten_rechts.jpg (47.11 KiB) Viewed 8101 times
Atari_TT_Rev_H_Rückseite_oben_rechts.jpg
Atari_TT_Rev_H_Rückseite_oben_rechts.jpg (22.59 KiB) Viewed 8101 times
Atari_TT_Rev_H_unten_links.jpg
Atari_TT_Rev_H_unten_links.jpg (43.35 KiB) Viewed 8101 times
Notice how the bottom left corner is green instead of metallic?


Let's look at another newer REV.H:
DSCF1294_s.jpg
DSCF1294_s.jpg (360.62 KiB) Viewed 8101 times
InkedTThf_LI.jpg
InkedTThf_LI.jpg (823.73 KiB) Viewed 8101 times
InkedTThe_LI.jpg
InkedTThe_LI.jpg (822.99 KiB) Viewed 8101 times
InkedTThd_LI.jpg
InkedTThd_LI.jpg (834.79 KiB) Viewed 8101 times
Now compare these pictures to yours.

So my conclusion so far is that if you were to turn the earlier REV.H around it would probably read C301763-001 REV D. I've never even seen a picture of a TT board with REV.D on the topside.
Steve
Posts: 2658
Joined: Fri Sep 15, 2017 11:49 am

Re: TT030 C302406-001 REV H

Post by Steve »

Very interesting. And yet none of them have that Yamaha chip mod. I would take it apart but it's kind of complicated, as it has got a PCB layer underneath it with an IC or two underneath.
tjam
Posts: 14
Joined: Sat Sep 07, 2019 9:12 am

Re: TT030 C302406-001 REV H

Post by tjam »

My eyes are pretty tired after I tried to figure out what is that quite big light green resistor located at near PSU connector and c120 capacitator :shock: :lol: Is that 10ohm resistor? I'll soon try to bring life to TT that has some components missing and that resistor is one of them.
Atarian Computing
Posts: 445
Joined: Tue Aug 22, 2017 4:27 am

Re: TT030 C302406-001 REV H

Post by Atarian Computing »

tjam wrote: Wed Dec 04, 2019 2:54 am My eyes are pretty tired after I tried to figure out what is that quite big light green resistor located at near PSU connector and c120 capacitator :shock: :lol: Is that 10ohm resistor? I'll soon try to bring life to TT that has some components missing and that resistor is one of them.
Yeah, you happened to run into one of the mysteries. It's marked as LD01 on the silkscreen. However, it does not appear in the schematic. I should know as I've painstakingly re-created it in KiCad.

It appears to be part of the TT ECL Video Subsystem. Components here get a letter "D" added after the regular designator. C becomes CD, R becomes RD, U becomes UD, etc. By that convention, LD01 would be L, which typically is a designator for a coil, inductor, bead, ferrite bead. It sure doesn't look like one. Also, there are no other "L" components on the whole board.

Based solely on looks, it could be a resistor or a capacitor. There are several smaller green resistor-looking caps on the board.

So, TL;DR is, no clue...
User avatar
ari.tao
Posts: 45
Joined: Tue Sep 18, 2018 8:50 am

Re: TT030 C302406-001 REV H

Post by ari.tao »

tjam wrote: Wed Dec 04, 2019 2:54 am My eyes are pretty tired after I tried to figure out what is that quite big light green resistor located at near PSU connector and c120 capacitator :shock: :lol: Is that 10ohm resistor? I'll soon try to bring life to TT that has some components missing and that resistor is one of them.
On my TT Rev.H it seems to be brown-black-black-gold.
But I can´t read what is written underneath.
Falcon, TT & some more
Atarian Computing
Posts: 445
Joined: Tue Aug 22, 2017 4:27 am

Re: TT030 C302406-001 REV H

Post by Atarian Computing »

Mine (REV.C - PGA model, C301763-001 REV A):
LD01.png
LD01.png (671.48 KiB) Viewed 6555 times
tjam
Posts: 14
Joined: Sat Sep 07, 2019 9:12 am

Re: TT030 C302406-001 REV H

Post by tjam »

Atarian Computing wrote: Wed Dec 04, 2019 4:20 pm Yeah, you happened to run into one of the mysteries. It's marked as LD01 on the silkscreen. However, it does not appear in the schematic. I should know as I've painstakingly re-created it in KiCad.

It appears to be part of the TT ECL Video Subsystem. Components here get a letter "D" added after the regular designator. C becomes CD, R becomes RD, U becomes UD, etc. By that convention, LD01 would be L, which typically is a designator for a coil, inductor, bead, ferrite bead. It sure doesn't look like one. Also, there are no other "L" components on the whole board.

Based solely on looks, it could be a resistor or a capacitor. There are several smaller green resistor-looking caps on the board.

So, TL;DR is, no clue...
Ah I see.. It surely looks odd, because it's quite big to be 10ohm resistor, but because of color coding I assumed it has to be resistor. I just figured out that axial caps and inductors also has color coding :stars: As far I can tell from pictures (I'm really not sure) it looks to have brown, black and black bands and 10% tolerance :lol: Probably it's not resistor because it's marked to be "L" component, but axial inductor :shrug:
Post Reply

Return to “TT”