Kenwood Hybrid IC KMA01

[wuffwaff]

Hi,

my old Kenwood CS4025 scope gave up last week. After searching for a while (which is quite difficult without a scope) I think the hybrid ic KMA01 is faulty. I looks like there are two opamps, a small cap, a fet or transistor and a resistor on it.
The simplest thing would be to get a new (used) one. The alternative would be to build a new one.

Does anyone know where to get a new one?
Does anyone have a schematic of the KMA01?

Thanks,

William

 

[JKCC]

Hi William,

I have same problem with a scope CS 4025 too. The source is with voltage values different in relation to manual service Kenwood .

I don't find high voltage in TRC.


and i don't find nothing about KMA01

 

[1triphet]

KENWOOD CS-4025 U1 KMA01 CIRCUIT schematic

 

[1triphet]

PCB KMA01

 

[theo1978]

Leader Scope with KMA01 fault

Hi.....
I am an electronic engineer and a new one in this forum!
I have the Leader 8040 scope with the same problem, KMA01 hybridr IC fault.
I downloaded your's KMA01 schematic and the picture with the pcb for a new one, handmade KMA01.
Do you know, where can I find a new one KMA01?
If there is no possibility to find a new one, Ok...I am going to build the handmade with your pcb.

Thank you very much!

 

[theo1978]

KMA01 Pcb placement

Dear Sir!
Can you send me the placement of the KMA01 pcb board components, because I believe it has some errors or I do a wrong component placement.

Thank you!

 

[1triphet]

KENWOOD CS-4025 U1 KMA01 CIRCUIT schematic

new Email triphet123@yahoo.co.th

 

[TonesB]

Schematic vs PCB of KMA01

I know this is a few years down the track but I would really appreciate some urgent help. I have an old cs-4025 that I'm trying to resurrect.
There are differences between the schematic and the PCB layout that 1triphet provided for the KMA01. The PCB seems to have a couple of errors? Pin 8 of TL072 seems to be shorted out to Pin4 of itself and theLM1458? Also pins 5 of the board is not connected but the schematic shows it's connected? The dual Op Amps in each IC (A & B) look like they've been transposed as well - though not a big issue? 7 and 9 have a jumper but nothing on the schematic. And some of the values are different?
Which diagram should I take as the definitive one? It looks like the schematic?
If anyone can help asap that would be much appreciated.
Thanks!

 

[Mr James]

Just in case anyone is ever interested, I recently repaired two of these.
The 33µF 15v electrolytic cap was replaced with a similar value tantalum and the TL072 was replaced like for like.

Hope this helps.

 

[wuffwaff]

Thanks for the Information,

it is just 10 years too late

After not being able to repair the Kenwood I sold it and bought a cheap digital one. I still miss the Kenwood as the resolution of the screen was much better.

William