Narrative:

Flight was originating after overnight maintenance for electrical problems including TR1 circuit breaker (circuit breaker) and equipment cooling fan circuit breaker being popped in flight. It was a normal preflight and pushback except for a fuel discrepancy due to the previous days out of service for maintenance. After engine start we noted the equipment cooling inop light illuminated and found the normal equipment cooling fan circuit breaker popped. We coordinated with dispatch and mx for a deferral off the gate then taxied for takeoff.after a normal departure climbing through approximately 15;000 ft the equipment cooling fan inop light illuminated again. We verified the switch in altitude per the QRH and the circuit breaker for the altitude fan was still in. I did a more comprehensive review of the previous day's write-ups and realized we might be following the same failure chain as the day before. We discussed alternates; coordinated with the F/a's (flight attendants) concerning the previous fumes write-up; and got dispatch on the radio to advise of our concerns. We had to radio because ACARS was also intermittent at that time. We were level at cruise when [a flight attendant] called to advise us there was an odor of hot electrical equipment in the aft galley and mid cabin but it was faint. We began to review the smoke/fumes checklist. A few minutes later she called again and said the odor was now stronger; no visible smoke; and she was feeling a bit nauseated and light headed. I told the F/a's to secure the cabin for a [diversion]; we donned our masked in the cockpit; and I asked the first officer (first officer) to [advise ATC] and begin the divert to [an airport] approximately 70 miles on our nose and VFR. As he began the descent I realized my mask microphone was intermittent at best so I told him to fly and talk while I ran the checklists and set us up for an approach. My mask worked to coordinate some checklist items with the F/a's and occasionally to coordinate with the first officer but mostly we were pointing and acknowledging with thumbs up or I was pulling my mask away to speak to him. As I completed the fumes checklist we got a pressurization auto fail light and shortly thereafter a cabin altitude warning horn. I switched from programming for the arrival to the qrc for cabin altitude warning horn. The cabin altitude was about 10;500 ft climbing slowly. I ran the checklist and with the outflow valve closed the cabin altitude immediately began a rapid descent. I went back to setting us up for approach. On downwind the left generator dropped off the bus and the first officer noticed it and asked if he should start the APU and put it on the bus. I affirmed that decision and he did so. At that point with landing numbers from the FMC; turning base to a long runway VFR I took the aircraft from the first officer and asked him to check my cockpit setup for approach. We noticed the cabin was over-pressurizing with about a 7psi differential and the aircraft at 8000 ft MSL so I directed the first officer to fully open the outflow valve and go to full cold on the packs. ATC asked us if we could slow for sequence and we said no we wanted to get on deck as soon as possible so they cleared the final and we continued in. At about 14 miles on the localizer the a autopilot failed so I began hand flying the decel and we began to configure. The field was in sight. At about five miles and approximately 3000 ft MSL and glideslope intercept; I lost all my primary flight instruments except altitude and my localizer/GS indicators. I looked over and realized my first officer still had instruments and passed control to him for the landing and continued to configure.completing the landing checklist we noted no green light on the flaps and antiskid inop. I decided based on the runway length and condition to continue after a quick visual check of the slats on both sides and advised the first officer to rollout with reverse and be easy on the brakes. On landing we had normal spoiler deployment but only the right reverser showed deployed despite both handles being up. I called the malfunction and the first officer adjusted reverse and maintained centerline for the rollout. After landing we cleared the runway and stopped. I decided to unmask so we could communicate and had to use the PA to get the F/a's to come up on the interphone because the F/a call was not working. I confirmed with them that there was no smoke in the cabin and they were ok with a taxi to a gate. I then made a PA to the passengers that we had experienced an electrical malfunction requiring a diversion for safety. I asked for their patience and told them we would taxi to a gate and begin accommodating their continued travel as soon as possible. We taxied to the gate and shut down. After the shutdown checklist I went to the back; checked on the F/a's; and again made a PA thanking the passengers for their patience and cooperation in re-accommodating them.

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Original NASA ASRS Text

Title: B737 flight crew reported a cascading electrical failure and fumes in the cabin.

Narrative: Flight was originating after overnight maintenance for electrical problems including TR1 circuit breaker (CB) and equipment cooling fan circuit breaker being popped in flight. It was a normal preflight and pushback except for a fuel discrepancy due to the previous days out of service for maintenance. After engine start we noted the Equipment Cooling Inop light illuminated and found the normal equipment cooling fan circuit breaker popped. We coordinated with Dispatch and MX for a deferral off the gate then taxied for takeoff.After a normal departure climbing through approximately 15;000 ft the Equipment Cooling Fan Inop light illuminated again. We verified the switch in ALT per the QRH and the circuit breaker for the ALT fan was still in. I did a more comprehensive review of the previous day's write-ups and realized we might be following the same failure chain as the day before. We discussed alternates; coordinated with the F/A's (Flight Attendants) concerning the previous fumes write-up; and got Dispatch on the radio to advise of our concerns. We had to radio because ACARS was also intermittent at that time. We were level at cruise when [a Flight Attendant] called to advise us there was an odor of hot electrical equipment in the aft galley and mid cabin but it was faint. We began to review the Smoke/Fumes Checklist. A few minutes later she called again and said the odor was now stronger; no visible smoke; and she was feeling a bit nauseated and light headed. I told the F/A's to secure the cabin for a [diversion]; we donned our masked in the cockpit; and I asked the F/O (First Officer) to [advise ATC] and begin the divert to [an airport] approximately 70 miles on our nose and VFR. As he began the descent I realized my mask MIC was intermittent at best so I told him to fly and talk while I ran the checklists and set us up for an approach. My mask worked to coordinate some checklist items with the F/A's and occasionally to coordinate with the F/O but mostly we were pointing and acknowledging with thumbs up or I was pulling my mask away to speak to him. As I completed the Fumes Checklist we got a Pressurization Auto Fail light and shortly thereafter a Cabin ALT Warning horn. I switched from programming for the arrival to the QRC for Cabin ALT Warning horn. The cabin altitude was about 10;500 ft climbing slowly. I ran the checklist and with the outflow valve closed the cabin altitude immediately began a rapid descent. I went back to setting us up for approach. On downwind the left generator dropped off the bus and the F/O noticed it and asked if he should start the APU and put it on the bus. I affirmed that decision and he did so. At that point with landing numbers from the FMC; turning base to a long runway VFR I took the aircraft from the F/O and asked him to check my cockpit setup for approach. We noticed the cabin was over-pressurizing with about a 7psi differential and the aircraft at 8000 ft MSL so I directed the F/O to fully open the outflow valve and go to full cold on the packs. ATC asked us if we could slow for sequence and we said no we wanted to get on deck as soon as possible so they cleared the final and we continued in. At about 14 miles on the Localizer the A autopilot failed so I began hand flying the DECEL and we began to configure. The field was in sight. At about five miles and approximately 3000 ft MSL and glideslope intercept; I lost all my primary flight instruments except altitude and my LOC/GS indicators. I looked over and realized my F/O still had instruments and passed control to him for the landing and continued to configure.Completing the Landing Checklist we noted no green light on the flaps and antiskid inop. I decided based on the runway length and condition to continue after a quick visual check of the slats on both sides and advised the F/O to rollout with reverse and be easy on the brakes. On landing we had normal spoiler deployment but only the right reverser showed deployed despite both handles being up. I called the malfunction and the F/O adjusted reverse and maintained centerline for the rollout. After landing we cleared the runway and stopped. I decided to unmask so we could communicate and had to use the PA to get the F/A's to come up on the interphone because the F/A Call was not working. I confirmed with them that there was no smoke in the cabin and they were ok with a taxi to a gate. I then made a PA to the Passengers that we had experienced an electrical malfunction requiring a diversion for safety. I asked for their patience and told them we would taxi to a gate and begin accommodating their continued travel as soon as possible. We taxied to the gate and shut down. After the Shutdown Checklist I went to the back; checked on the F/A's; and again made a PA thanking the Passengers for their patience and cooperation in re-accommodating them.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.