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Hi from the newbie.

W?NKY All Messages By This Member #41317 Hi all. I've acquired a new to me dead QRO 2500DX (S/N 5461) that looks really clean inside and out. It does power up and completes the warm up but no keying for XMIT. I'm just getting started diagnosing.? Story goes, it was running fine when a "pop" was heard.? Immediately shut down and a large dead spider was found inside.? A "buddy that's a great tech" diagnosed as bad "protection" chip. I took a quick look and it appears he was referring to a plug in 555 timer DIP??? What is the street reputation for this amp?? Does the story sound reasonable.? Tips or Advise? BTW, both meter lamps are out.? I'm hoping to retrofit leds?? TIA 73
Louis Parascondola All Messages By This Member #41318 The 555 timer chip is for the wait timer. ?Takes about 180 seconds or so for the ready timer to complete. ?The amp doesn’t have a safety chip so tech is off base. ?Check the low voltage bridge circuit, sometimes they go. toggle quoted message Show quoted text On Monday, May 19, 2025, 11:29 AM, W?NKY <Phrede@...> wrote: Hi all. I've acquired a new to me dead QRO 2500DX (S/N 5461) that looks really clean inside and out. It does power up and completes the warm up but no keying for XMIT. I'm just getting started diagnosing.? Story goes, it was running fine when a "pop" was heard.? Immediately shut down and a large dead spider was found inside.? A "buddy that's a great tech" diagnosed as bad "protection" chip. I took a quick look and it appears he was referring to a plug in 555 timer DIP??? What is the street reputation for this amp?? Does the story sound reasonable.? Tips or Advise? BTW, both meter lamps are out.? I'm hoping to retrofit leds?? TIA 73
Dave w6de All Messages By This Member #41319 开云体育 Lou has it right.? Not a 555 timer problem because, as per your description, the timer circuit is working. ? I have no familiarity with QRO Amplifiers other that they looked good and had a good reputation. ? Do you have the manual?? There is a Trouble Shooting chart in the manual with sections for both the panel lights and Amplifier will not key. ? A pop at failure indicates a fuse blowing or a component destruction.? A visual inspection of the areas the Troubleshooting guide describes for the potential failures might show the component destroyed.? Remove the fuses and check them with an ohm meter. ? Also, the Pop may have been caused by a tube failure.? So, after the repair proceed cautiously.? If possible have the tubes tested before you fire it up again. ? 73, Dave, w6de ? toggle quoted message Show quoted text From: [email protected] <[email protected]> On Behalf Of W?NKY via groups.io Sent: 19 May, 2025 13:09 To: [email protected] Subject: [ham-amplifiers] Hi from the newbie. ? Hi all. I've acquired a new to me dead QRO 2500DX (S/N 5461) that looks really clean inside and out. It does power up and completes the warm up but no keying for XMIT. I'm just getting started diagnosing.? Story goes, it was running fine when a "pop" was heard.? Immediately shut down and a large dead spider was found inside.? A "buddy that's a great tech" diagnosed as bad "protection" chip. I took a quick look and it appears he was referring to a plug in 555 timer DIP??? What is the street reputation for this amp?? Does the story sound reasonable.? Tips or Advise? BTW, both meter lamps are out.? I'm hoping to retrofit leds?? TIA 73
Dave w6de All Messages By This Member #41320 开云体育 I forgot to add.? You don’t know when the spider died in the Amp.? If the spider was intact it probably entered and died after the amp was placed in storage. ? toggle quoted message Show quoted text From: [email protected] <[email protected]> On Behalf Of Dave w6de via groups.io Sent: 19 May, 2025 23:34 To: [email protected] Subject: Re: [ham-amplifiers] Hi from the newbie. ? Lou has it right.? Not a 555 timer problem because, as per your description, the timer circuit is working. ? I have no familiarity with QRO Amplifiers other that they looked good and had a good reputation. ? Do you have the manual?? There is a Trouble Shooting chart in the manual with sections for both the panel lights and Amplifier will not key. ? A pop at failure indicates a fuse blowing or a component destruction.? A visual inspection of the areas the Troubleshooting guide describes for the potential failures might show the component destroyed.? Remove the fuses and check them with an ohm meter. ? Also, the Pop may have been caused by a tube failure.? So, after the repair proceed cautiously.? If possible have the tubes tested before you fire it up again. ? 73, Dave, w6de ? From: [email protected] <[email protected]> On Behalf Of W?NKY via groups.io Sent: 19 May, 2025 13:09 To: [email protected] Subject: [ham-amplifiers] Hi from the newbie. ? Hi all. I've acquired a new to me dead QRO 2500DX (S/N 5461) that looks really clean inside and out. It does power up and completes the warm up but no keying for XMIT. I'm just getting started diagnosing.? Story goes, it was running fine when a "pop" was heard.? Immediately shut down and a large dead spider was found inside.? A "buddy that's a great tech" diagnosed as bad "protection" chip. I took a quick look and it appears he was referring to a plug in 555 timer DIP??? What is the street reputation for this amp?? Does the story sound reasonable.? Tips or Advise? BTW, both meter lamps are out.? I'm hoping to retrofit leds?? TIA 73

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