| Author |
Message |
    
Dxmodulator
Junior Member
Username: Dxmodulator
Post Number: 46
Registered: 11-2004
| | Posted on Monday, September 11, 2006 - 9:37 am: | 
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Ok here we go, the radio is on my bench with a blown trace on the circuit board, right where the positive power lead is soldred to the board. It looks as if someone tried to fix this with a jumper across the blown trace (the jumper also looks as if it were blown). I think someone hooked the power leads up backwards. This radio has already been expanded by some one else. Well after lookin and searching with probs I found out the diode D-48 has a short acress it checking both ways (Cathode to Anode) and vice versa. This Diode connects across the positive and negative leads. The whole problem is the radio does not power up. Should have said that from the beginning. Are there any other componets in this area of the board I should be lookin at to get this radio powered up Besides replacing the D-48? This radio looks new it still had the little advertisement stuck to the top if the radio. Thank you for all your help. |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 2064
Registered: 9-2004
| | Posted on Monday, September 11, 2006 - 11:28 pm: |
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i have never worked on,or seen the insides of a 200gtldx.
that being said, it really sounds like D48 is the reverse polarity diode.
i would replace it, and make sure that both the positive and negative power wires are fused.
good luck,
matt |
Dxmodulator
Junior Member
Username: Dxmodulator
Post Number: 48
Registered: 11-2004
| | Posted on Wednesday, September 13, 2006 - 9:26 am: |
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Well I replaced the Diode D-48. It still does not power up. My be it is time to send it to cobra for repair. |
Dxmodulator
Member
Username: Dxmodulator
Post Number: 53
Registered: 11-2004
| | Posted on Monday, September 18, 2006 - 8:52 am: |
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Does any one know any thing more about the above problem with no power to the radio? |
Inspector
Intermediate Member
Username: Inspector
Post Number: 163
Registered: 12-2001
| | Posted on Wednesday, September 20, 2006 - 2:21 am: |
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Follow the +voltage, from the connection at the board, and you may find another small blown trace. Check both sides of the on-off switch. I have seen where the +DC trace acts like a fuse and blows at usually a narow spot or real close to the switch |
Kid_vicious
Senior Member
Username: Kid_vicious
Post Number: 2089
Registered: 9-2004
| | Posted on Wednesday, September 20, 2006 - 10:39 pm: |
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good advice inspector!
good to see you on the board, hope to see you around more often. we need you!
matt |
Dxmodulator
Member
Username: Dxmodulator
Post Number: 57
Registered: 11-2004
| | Posted on Thursday, September 21, 2006 - 8:03 pm: |
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I followed the wires from the board to the power switch. I bypassed the switch and still no power. I am at a road block with this project. |
Bullfrog13x4
Member
Username: Bullfrog13x4
Post Number: 50
Registered: 3-2006
| | Posted on Monday, September 25, 2006 - 1:29 am: |
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get a schematic or look it up online and follow the circut until you run out of fried parts to replace and wala. hope you are good at using a high powered telescope. or call cobra and see if they will let you use it as a trade in for 25% off.
bullfrog13x4 |
Dxmodulator
Member
Username: Dxmodulator
Post Number: 69
Registered: 11-2004
| | Posted on Sunday, October 22, 2006 - 10:54 am: |
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OK update
Took this radio to a friend and he fixed it. Part of the blown trace was still not connected with the rest of the board. A jumper and some solder fixed it. Now how do I peak and tune it and what kind of output numbers should I be lookin for? What fuse should I use on the power cord. There was a 10 amp fuse with it when I got it and those fuses failed until I put a 15 amp fuse in it. |
Ck29
Junior Member
Username: Ck29
Post Number: 40
Registered: 3-2006
| | Posted on Sunday, October 22, 2006 - 1:35 pm: |
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You can try cb tricks they have all the alignment info that you will need. If you have read all my past posts you will be able to read the different experiences I have gone thru with the cobra 200, Further more on some of your questions, this morning I did a inspection of my cobra 200 that came back from warranty repair again. Pre driver is set to about .55ma , driver set to 1.0a , AM low pwr 6w dead key to 60 p.e.p., high pwr 35w dead key to 130p.e.p. using a 1 khz tone. Modulation was set to 110% MAX and AVG was about 90% using a DM-452 mic. FM Dev was set to 4.5 kHz max. Fuse rating that was installed from the factory is a 20amp.
Note: I would suggest to be conservative on all your adjustments and hang a rabbits foot from channel knob
Hope this helps, good luck
73s |
