Hi Bob,
Thanks for the reply .The falt is within the Regulator. Jeff NZ2S sent me a "Mod Sheet" The Mod was written by DL2CE.
The regulator? "will only turn on when cold? the problem is probably caused by self oscillationinternal within? the chip"
?Changing the the capacitance of C6. Cures the problem!
Here is the link to the Mod.??? ??
Hope this helps,
73,
Richard G0ILN
On 19 July 2023 at 15:13 Bob <W4JFABob@...> wrote:
If I understand correctly, the problem was a capacitor, not the regulator IC?
Bob W4JFA?
Hi ,
Just an update on my Kenwood TM255 2Mtr multi-mode.
I could not get hold of the Regulator chip L78LR05-FA. So I used the get-around suggested by Jeff NZ2S.? I have never tried to solder SMD parts before . I had to resolder the regulator as I had removed it thinking I could buy a new one!
I found a new 22uF? Tantal (Reccomended was 5-15uF). In my spares and fitted it. WOW it worked to my surprise!
So thank you? Jeff,Bob ,Eric and any one I have missed out.
73
Richard G0ILN
On 10 July 2023 at 13:16 JeffBanke <jeffbanke@...> wrote:
Glad to help, and good luck with it!
Jeff - NZ2S
On Mon, Jul 10, 2023 at 3:02?AM Richard Putnam <
kairos1@...> wrote:
Hi Jeff,
Many thanks for the work you have put in to help me out.
The get around seems to be the best bet.
The problem as explained in the write up is exactly what my problem is. so I will try the capacitor mod.
I wish now I hadn't taken the old regulator off the board. I hope I haven't damaged it!
Thanks again,
Richard
On 09 July 2023 at 16:01 JeffBanke <jeffbanke@...> wrote:
Digikey has alternative names for the device
| ATTRIBUTE |
DESCRIPTION |
| Other Names |
ONSONSL78LR05B-FA-E
2156-L78LR05B-FA-E
|
These folks seem to have some:
Here is a mod specific to that regulator and radio that you might look into
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Jeff - NZ2S
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Jeff - NZ2S
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