Suffix resistors.

[N9ZN-Extra]

Obviously anyone can change the suffix resistor placement on a board so the board appears to have a different suffix.

My question is will the board then take on the charistics of the changed suffix or are the suffix resistors only irrelevant marking objects?


From viewing a board, and schematics, it appears there is no electrical significance for the suffix resistors. Is this correct? If this is correct then I suppose the only relevant reason for having resistors / jumpers placed on the suffix portion of the board is to verify the software used during board manufactoring (CAM). Otherwise the suffix could have been stamped on the board if just for visual observation.

[tom66]

Re: Suffix resistors.

Marking only. Resistors like that cost basically nothing, cheaper than having someone mark each board by hand.

I think the board might test them, but the boards will not usually have software on them for all revisions. So swapping the resistors will not work. In addition things like ports or tuners change between modules.

Would be interesting to see what changing them does - if anything...

[budm]

Re: Suffix resistors.

"the suffix resistor" do you mean the component value or the component designator (I.E. R1, R2, C5, C7, etc.)
The value of the component may be changed on the the particular PCBA (Printed Circuit Board Assembly), when they do that, the PCBA will rev up to the new revision using ECO in keep track of the design changes. The PCBA numbers and rev are usually on the barcode sticker. The PCB (blank board) will have PCBA numbers and REV # silk screened right on the board.

[tom66]

Re: Suffix resistors.

He means these, I think
https://www.youtube.com/watch?v=Irfe...direct=1&t=58s

[N9ZN-Extra]

Re: Suffix resistors.

He means these, I think
https://www.youtube.com/watch?v=Irfe...direct=1&t=58s

That is correct tom66.

When I said the relevance of using resistors to indicate the board suffix was to verify software. What I ment is during the Computer Aided Manufacturing (CAM) process the software drives the selection of components to be placed on the boards, the placement area, and any other assembly line computerized functions like fine tuning. By using resistors soldered on the board that in itself is validation of which CAM software was used to control the manufacturing of the circuit board. Something a printed label or otherwise written indication could not verify. Having this under automated control would be very essential when so many diffrent TV models are being driven by the same circuit board etching design with potentially differing components, adjustments, and EEPROM data.

It would make since to me, from a manufacturing prespective, to indicate SUFFIX in this mannor because it relieves any possibility of human error. Especially when Panasonic has chosen to use the same basic etching design for the main (A) board across all TV's in the series (ST30/PST34 in my case) produced during a given year. I have not verified if the manufacturing board number combined with the suffix has direct correlation to Panasonics part numbers but I bet they do.

This is not a big deal for most folks UNLESS THEY BUY A USED MAIN BOARD FROM SOMEONE ON eBay, Amazon, Yahoo, or another similar site including Hi DEF TV forums as I did and the CAUTION FLAG NEEDS TO COME OUT. I became confused about main board compatibility when several sellers on a site advertised cross compatibility between different TV models one of which was the TC-P42ST30 that I own. Now after coming to this forum and browing shopjimmys.com I understand this not true for my TV, there is only one main board made to control it. My point is everyone on this site and others should keep this in mind because users, thinking they purchased correct components for repairs, may be under the wrong impression at no fault of their own. We humans tend to be too trustful at times and when sellers offering hundreds of parts makes a statement we (myself anyway) have a tendancy to believe them never realizing we may not have purchased what we need.

All of this brings me back to the discussion in another forum about swapping Flash IC's between main boards, in retrospect this may not be a wise idea to try with my perfectly functioning TV. It could cause the overdriving of components beyond what they are specified to handle creating trouble in other areas. I would really hate it if I damage my good TV for an adventure in HI DEF electronics. Maybe when I find some similar customer throw aways that I can repair that may be the wiindow for experimentation.

These are all assumptions, related to sequence numbers, but until someone can explain this better I will assume these assumptions are correct.

[civi]

Re: Suffix resistors.

@N9ZN-Extra: Hi, I don’t think so the suffix codes have any electrical significance on the PCB and nothing to do with the software testing as I think these are the codes only for the identification of the resistors on the PCB