Midbanding an amstrad 900

[Buick Mackane]

i just looked at an old Amstrad board and transistor is in correct.

Lovely Get it stuck in a jiffy bag and post it up to me

[JollyRoger]

A jc501 should be OK as it's shown as a comparison

[Buick Mackane]

A jc501 should be OK as it's shown as a comparison

Yeah another blank drawn, This is turning into the longest thread on TM1 And possibly TM1's biggest ever stumper Even nick is losing the will to live

[Ashtec]

MID BLOCK(EU)LC7132 BAND CONVERSION INVERTER BOARD FOR AMSTRAD/COMM NEG DISPLAYS

http://www.ebay.co.uk/itm/MID-BLOCK-EU- ... 1c36f47180

[Buick Mackane]

MID BLOCK(EU)LC7132 BAND CONVERSION INVERTER BOARD FOR AMSTRAD/COMM NEG DISPLAYS

http://www.ebay.co.uk/itm/MID-BLOCK-EU- ... 1c36f47180

Does he sell bleep boards?

Who is that guy anyway? Im sure hes on here

[Buick Mackane]

Complete bleep circuit with parts substituted,

[JollyRoger]

Complete bleep circuit with parts substituted,

C125 is 1nF ( .001mfd ) marking on cap 102 not 0.01nF it's getting late

[Buick Mackane]

Complete bleep circuit with parts substituted,

C125 is 1nF ( .001mfd ) marking on cap 102 not 0.01nF it's getting late

Yes my mistake, Its been a total BLEEP of a BLEEPING day Im allowed one (maybe two) mistakes

[JollyRoger]

Well I have just fitted all the components to a Harvard 402 MPA for the bleep which is the same radio as the amstrad 901 and the bleep works perfect using the original components and then changed them for your component substitutes, so all I can say is check components around Q20 and C111 and make sure you haven't left anything out as there is nothing more I can think why it isn't working unless it was here on my workbench. but it's such a simple circuit it should be working unless there is a faulty component.

[Buick Mackane]

Well I have just fitted all the components to a Harvard 402 MPA for the bleep which is the same radio as the amstrad 901 and the bleep works perfect

Rub it in jolly why dont ya I rechecked the components lastnight & checked the trackside using an eye piece, Nothing obvious to me, Must be a faulty component,

[JollyRoger]

Try changing Q20 an C111 making sure c111 is 3.3 uf at 16 v

[Buick Mackane]

Try changing Q20 an C111 making sure c111 is 3.3 uf at 16 v

Iv'e already changed Q20, But i'l change it again with C111 and report back

[JollyRoger]

Try changing Q20 an C111 making sure c111 is 3.3 uf at 16 v

Iv'e already changed Q20, But i'l change it again with C111 and report back

also check your homebrew R95 1.8K is 1.8K and not 1.8 ohm

[Buick Mackane]

Try changing Q20 an C111 making sure c111 is 3.3 uf at 16 v

Iv'e already changed Q20, But i'l change it again with C111 and report back

also check your homebrew R95 1.8K is 1.8K and not 1.8 ohm

Ive checked the b@st*rd 100 times Just changed Q20 (3RD time) and C111, zilch

[JollyRoger]

nowt worse than a simple circuit doing ya head in.

I only did mine this morning to see if I came across the same problem, but no, it wasn't to be.