Sold A600 RGBtoHDMI PLCC version

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Reflowed denise, still got a blue cast.

Denise seems to be misaligned front to back about a third of a pin width - so my theory is that potentially some pins could be getting bridged.

Here's the sequence of events:

Board arrived, would not stay clipped on.

Sanded board and it stayed on - image was perfect.

Decided to downgrade the 32gb micro SD for a spare 1gb card I have laying about.

Machine now exhibiting blue tinge - from HDMI & from the RGB port.

Reflowed Denise, & kaptan taped the left and right side to avoid the PLCC pins contacting the pcb inadvertently - still blue tinge.

Any suggestions?
 
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Reflowed denise, still got a blue cast.

Denise seems to be misaligned front to back about a third of a pin width - so my theory is that potentially some pins could be getting bridged.

Here's the sequence of events:

Board arrived, would not stay clipped on.

Sanded board and it stayed on - image was perfect.

Decided to downgrade the 32gb micro SD for a spare 1gb card I have laying about.

Machine now exhibiting blue tinge - from HDMI & from the RGB port.

Reflowed Denise, & kaptan taped the left and right side to avoid the PLCC pins contacting the pcb inadvertently - still blue tinge.

Any suggestions?

Without the RGBtoHDMI pluged, the DB23 output still blue tinge ?
Can you share macro picture of all Denise pins and check the continuity to U31 and U32 ?

cO9WLZC - Imgur.jpg
 
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Without the adapter plugged in DB23 image is normal.

I'll take some pics & check continuity after work - thanks.
 
Can you share macro picture of all Denise pins and check the continuity to U31 and U32 ?

Tested connectivity and that's fine.

Pics below, the side next to the 28mhz crystal is the worst in terms of denise alignment, but all the pins are solidly anchored.

top side
ACtC-3en7lPFOqfYPZBT6JfztRrH7pyR3GzdI1nUBqlNerMRA1UXevNnNhM__TT0syki2YnN5EteRoD6sWX0p9jP0UWFLtlJWeIGD2F-HYGW3VsuZoavrhdBc4vtyr7Pkj7xjF9y6HwcJtovOBbZzE7umywTsQ=w845-h475-no


bottom
ACtC-3f3n2Qy9Y5PJK4Y_CfLk95x8ZFuKqjjMcqafhr4A7fSaC4OUfaudVwYozquX2FUILnsIQaaWFV0XkOiYZNty6LHv7IeSLlsH_9aDiT_20V0wYov8ylZSlzF2S3lUQaoHlyx01xfiNhwpLko_h4LHPiBcA=w845-h475-no


left - some flux residue that I need to flush
ACtC-3f7WEq-1lU2JLWeiYzz39QHb1EK1K7m7DrDpaWMj9eqfrk9Ic50mLUBThPPst2qNGX3XNZ2GKiB29ENciuOUkdF29uz8dI6PvL-oHVLv9mTjVKw267LdMccRaxIJ0W4FEGDbIlFhjOehHDtdD-kcncC9w=w845-h475-no


right - hardest to photo due to the close crystal
ACtC-3eFk29qaqn39PydfK2blmvSxkUhNQAk2tYsk1p8vA-04XVfDc1G4izjKlOusLi6gXneMv4b8-0PQk5Ka3RWlhYMGUObfnEiAPmSDVmKFj1ISAuHzL00aMm7c7dyLTVt9YZa_IXC6w474erCESl4VIu1Ew=w845-h475-no
 
Can you share macro picture of all Denise pins and check the continuity to U31 and U32 ?

Tested connectivity and that's fine.

Pics below, the side next to the 28mhz crystal is the worst in terms of denise alignment, but all the pins are solidly anchored.

Can you put a screenshot from kiskstart and AmigaTestKit in color test - F6 Video menu) to understand the "blue tinge" (RGBtoHDMI can do a screenshot with a single press on osd button).
 
Looks to me like the high red bit is NC or tied to 0 (not sure if that would be high or low on denise).

Didn't bother with kickstart as this screenshot says it all...

ACtC-3dn4zdvx7ZsyTEsBP_dIyM2Hyhl4aWjE6kX2uGo0BwogZYIJHEYej6iCspZbCWuvo6tqM9wnIjada0N5EzTpnm_oOzJeCbTsz65j2lSDo7GdPTddBkvdFIciHDfrSlN7piszN5M536juv3wJQeUDLGR7A=w1743-h1307-no


Apologies if this shows huge.
 
OK, so there's 75ohms resistance showing between R3 and ground on the adapter... R3 has good connectivity to U3 pin 4, but there's still 75ohm to ground from that pin. Has the flip flop gone bad? It worked originally, at no stage have I had this powered whilst the plcc wasn't clipping on well. I can't see an obvious bridge/partial bridge to ground anywhere on that trace, and I don't see any passives in line either.
 
OK, so there's 75ohms resistance showing between R3 and ground on the adapter... R3 has good connectivity to U3 pin 4, but there's still 75ohm to ground from that pin. Has the flip flop gone bad? It worked originally, at no stage have I had this powered whilst the plcc wasn't clipping on well. I can't see an obvious bridge/partial bridge to ground anywhere on that trace, and I don't see any passives in line either.

I have a similar problem, but in my case I found the problem... My RPiZero is faulty...
Two screen, same adapter, but not same Pi ��
2021-05-29_01.16.14.jpg
 
I think I'll remove the flip flop with hot air and see if R3 still shows 75ohm to ground.
 
I think I'll remove the flip flop with hot air and see if R3 still shows 75ohm to ground.

Done this and there's no longer a partial short, so there's no issue with the PLCC socket. I'll solder the flip flop back on and see what gives - there's no internal short between pin 1 (GND) and pin 4 (R3).

EDIT - soldered it back on and no change.
 
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