It was erraticly posted. Sorry

No problem -- I'll get back to you later on (the usual time)

Best regards
HP

 

@patpin

Did you see post #156?

Best regards
HP

 

Please be advised that there are many other 'things' to examine/inspect -- howbeit I prefer a 'first things first' approach
HP

Hallo, been on the road yesterd. I think theoretically yr right preferring the step by step approach. But in this case (see picture) it is a delicate work to get the time div out, and I will naturally do it, but I would prefer that we can measure everything behind the time/div block in one session. Is there anything hidden aft that we can check/or measure while the block is out?

if you dont have the PCB layout I will post it. K.reg

 

Hallo, been on the road yesterd. I think theoretically yr right preferring the step by step approach. But in this case (see picture) it is a delicate work to get the time div out, and I will naturally do it, but I would prefer that we can measure everything behind the time/div block in one session. Is there anything hidden aft that we can check/or measure while the block is out?
View attachment 99016
if you dont have the PCB layout I will post it. K.reg

I apologize that I failed to correctly express myself -- I concur with your assessment that the difficulty attendant to removal of C56 is unwarranted at this time --- Hence, my suggestion that you measure the EMF across same (e.g. from the 'left end' of R124 to the chassis/ground)

Best regards
HP

 

Is there anything hidden aft that we can check/or measure while the block is out?

Perhaps -- however, if the (above described) EMF ('voltage') measurement is readily accomplished -- let's do that first... Ok?

 

I apologize that I failed to correctly express myself -- I concur with your assessment that the difficulty attendant to removal of C56 is unwarranted at this time --- Hence, my suggestion that you measure the EMF across same (e.g. from the 'left end' of R124 to the chassis/ground)

Best regards
HP

At the right of R124 11V; at the left 93V;

 

At the right of R124 11V; at the left 93V;

Sorry Type: At the right of R124 111V !!

 

Sorry Type: At the right of R124 111V !!

But what is the EMF reading from the left side of R124 to the chassis?

 

the left 93V;

Ah! Sorry! -- I missed that! --- Ok that looks consistent!

 

At the right of R124 11V; at the left 93V;

 

At the left no typo...; 93 V

 

At the left no typo...; 93 V

Top of R80: 92.7; below: 68V
Below of R56: 10.5 V

 

Note however that C56 is not entirely exonerated -- while ≈ 3.2mA is (IMO) consistent with anticipated current requirements, the Cap may, nonetheless, be 'open' -- (i.e. given the 'periodic' nature of the current demand, greater E(C56) might reasonably be expected) -- So one more test -- then we'll move on to other components for the nonce:

Please watch the EMF across C56 while the scope is functioning properly (during warm-up)

 

Note however that C56 is not entirely exonerated -- while ≈ 3.2mA is (IMO) consistent with anticipated current requirements, the Cap may, nonetheless, be 'open' -- (i.e. given the 'periodic' nature of the current demand, greater E(C56) might reasonably be expected) -- So one more test -- then we'll move on to other components for the nonce:

Please watch the EMF across C56 while the scope is functioning properly (during warm-up)

OK I let it cool down for 10 min. CU later.

 

At the left no typo...; 93 V

I didn't think there was -- An 18V drop is about what I'd expect (bearing the caveat in post #173 in mind)

Top of R80: 92.7; below: 68V
Below of R56: 10.5 V

Thank you! -- We'll analyze this following the 'warm-up test' described in post #173

 

OK I let it cool down for 10 min. CU later.

Didnt showed baseline over full screen at startup this time. I guess cool down period wasnt long enough.. I let it cool down 1/2 u. in cooler room.

 

@patpin

In case I'm (temporarily) absent when you've completed the 'warm-up test' -- please:

For the following tests only - Set the Time/Div control to 'EXT X' -- and the gain of the channel servicing the X-axis input to its lowest (i.e. least sensitive) range...

→'Re-take' the R80 & R56 measurements
Then ...
→The EMF across R64
→The EMF across R65
→The EMF across D55 (i.e. Ebe of TR26)
→The EMF from Test Point 'H' to the chassis

Please tabulate your results


Best regards
HP

 

Didnt showed baseline over full screen at startup this time. I guess cool down period wasnt long enough.. I let it cool down 1/2 u. in cooler room.

I may be away form my computer for a awhile --- So.. Once obtained, please post your results -- then proceed to the EMF measurements suggested in post #177

Best regards
HP

 

@patpin

In case I'm (temporarily) absent when you've completed the 'warm-up test' -- please:

For the following tests only - Set the Time/Div control to 'EXT X' -- and the gain of the channel servicing the X-axis input to its lowest (i.e. least sensitive) range...

→'Re-take' the R80 & R56 measurements
Then ...
→The EMF across R64
→The EMF across R65
→The EMF across D55 (i.e. Ebe of TR26)
→The EMF from Test Point 'H' to the chassis

Please tabulate your results


Best regards
HP

NON- EXT-X ---------- EXT-X
R80 TOP 91.8 ---------- 91.2
R80 BELOW 67 ---------- 66.8
R56 BELOW 10.3 ---------- =
over R64 -1.7 ---------- =
over R65 -9.7 ---------- =
over D55 0.6 ---------- =
point H -7.8 ---------- +1.3

The warmup phase with full screen did not occured even after 2h cooling.
k.reg (tabulator is mistery for me...functions when edited but not when published)

 

tabulator is mistery for me...functions when edited but not when published

That's because the character pitch used in the 'editor' differs from that of posted text --- No problem!

over R64 -1.7 ---------- =
over R65 -9.7 ---------- =

Please identify the position of the positive probe while taking each of the above readings...


Very best regards
HP


PS what does "K.Reg" mean?