Randall RG100G3 powerFET amp

"no name", not Hitachi ,2Sk1058 failed in low power practise use. Securing screw to h/s was fine . Known problem of Randall using suspect devices? probably 2006 PbF/RoHS labels

Reply to
N_Cook
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"Nutcase Kook "

** Only Hitachi or Renesas make them.

Sometimes logos are omitted from the packs.

** How the f*ck would you know that ?

FFS - report customer stories as STORIES !!

What is the nature of the failure?

Why do you EDIT all the facts out of your bullshit posts.

... Phil

Reply to
Phil Allison

More evidence of dodgey sourcing. The mounting hole is visibly off-centre relative to the hole in the flange, displaced vertically. Looking under x30 one of the 3 injection casting vent holes has this "ident" impressed in the 1.3mm diameter recess MALAYSIA AG

8 also a presumed date code of 6F1 marked under the K1058 for th earchives, but no maker name or logo This was D-S short failure
Reply to
N_Cook

Off centre hole is 0.3mm displaced vertically. No first rank manufacturer would have that amount of engineering departure from the industry TOP3 dimensions

Reply to
N_Cook

"Nutcase Kook"

** Think you at clutching at straws instead of getting the amp fixed.

That FET has been working fine in the amp for many years - so it is not likely to be a fake or dud.

..... Phil

Reply to
Phil Allison

I could not read the device number on the only other transistor on the pa board. Required my PTFE magic trick to read it. Will add a bit of heatsink to this TO220 . TR7 on overlay marked TRF820 TR 542P

7D and 83 impressed in the casting vent hole plastic again no logo or makers name no data found in wwwland "passing off " as IRF820 ? its not a bipolar transistor, the T of TRF is about the only readable letter without PTFE, so not an I.
Reply to
N_Cook

"Nutcase Kook"

** FFS - the full schematic is easy to find:

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Click on the thumb size schem at the bottom of the first post.

.... Phil

Reply to
Phil Allison

Back working again replacing the TRF820 and 2SK1058 principally. I would not have expected to see just 1Kohm separating the gate of an FET from the anode of a valve.

Reply to
N_Cook

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